Electropneumatic hammer



Dec. 28 1926. 1,612,113`

- A. C. J. GUNE ELECTROPNUMATIC HAMMER Filed sept, 5o, 1924 2 Sheets-Sheet l Dec. 2s, 1926. 1,612,113

' A. C.'J. GUNE ELECTROPNEUMATI C l- HAMMER Filed sept. 3o, 1924 2 sheets-sneu H32 29 7 28 'all Patented Der.. 2S, 1926.

unirse stares ALBERT CHARLES JAMES GUNE, OF FONTENAY SOUS BOIS, FRANCE.

ELECTROENEMATIC HAIl/TJER.

Application filed September 3G, 1924, Serial No. 740,851, and in France October 6, 1923.

The present invention relates to kan electro-pneumatic hammer in which the movable element or striker serving to produce the impact is actuated in the direction oi' the work by compressed air, or more generally by the expansion ot a compressed gas or vapour, or any suitable fluid under pressure, and is brought back by the action oi an electro-magnet, the heat which is lostin the electro-magnet being utilized for heating the air or gas when entering the power cylinder.

The valve gear for the compressed air supply comprises two arrangements, one 'lier the admission and a second for the discharge, these being independent ot each other and each controlled by an electro-magnet. For the sake of simplicity, the said Vvalve gear comprises ordinary slide valves controlled by reaction springs. Y

The striker may also be brought back by the electro-magnet controlling the discharge valve, provided the said striker opens the gas outlet ports somewhat before the end of its stroke; in this manner the electromagnet will only come into action to bring back the striker after the impact has taken place, and therefore will not diminish the intensity of the latter.

ln order to avoid all causes of damage to the apparatus should the striker be operated when the tool is out of contact with the work, the impact in the present 'device is not produced directly upon the head of the tool, but upon an intermediate element or anvil which is slidable in the axial direction and is provided with an apertured Hangs. Then the said anvil is not driven back by the thrust upon the tool, it closes the orifices by which the air may escape during the descent of the striker, and an air cushion will thus be torni-ed below the said anvil by which the shock will be absorbed. y

The humilier is actuated by a motor ot any suitable kind, hydraulic, electric or thermic, which serves to operate an alternator as well as an air compressor.

The said alternator is of the self-excited type and supplies alternating current to the electrounagnets of the hammer through the medium et a rotatable switch, and it comprises continuous current winding which on the one hand furnishes the exciting current and on the other hand supplies current -for the control of an electro-magnetic clutch which will be hereinafter specilied.

The 'frequency of the alternator should exceed that of the hammer, so that each electro-magnet may be energized, in the proper conditions as regards opening and closing the circuit; `the ratio between the frequency ot.' the alternating current and the `frequency oit the shocks produced by the striker is an integer in the present case.

rlhe said compressor is actuated by the motor through the medium of an electromagnet clutch, and it delivers compressed air into suitable storage tanks; when the pressure in the latter becomes suilicient, a pressure regulator will operate in order to break the circuit of the said clutch.

lt may prove advisable in eases in which the hammer is required to operate only in an intermittent mannert`or example in riveting work, that the compressor should be put in action only during the stopping periods oit' the motor. The compressor can be stopped by breaking` the circuit ot the said clutch when the hammer is set in operation.

The current passes through the said rotatable switch and then into a small switch which is mounted upon the handle of the tool. ln order to reduce the power of the hammer, and chiefly when starting, the latter switch may be so devised that it will close the circuit of the electro-magnets through one or more resistances, then shortcircuiting the latter.

Obviously, a motor such as described may supply power to vvarious hammers, this depending solely upon the size and power oit the said motor relative to the number ot hammers employed.

rllhe appended drawing shows by way of example an embodiment of the said inv-ention.

l is a general view ot the hammer, partly in elevation and partly in section.

Fig. 2 shows the control device of the hammer.

3 vis a voltage diagram showing the manner in which the various periods of the alternating current are utilized to energize the electro-magnet.

Fig. fl shows the arrangement of the circuits for the valve gear.

rllhe said hammer, Fig. l, essentially c01nprises a main body l consisting of various parts, upon which is disposed the operating handle 2. The cylinder 3 is coaxial with the said body. and has movable therein the gli piston or striker 4, said cylinder communicating at the top with the compressed air inlet 5. The admission of the said air into the cylinder 3 is controlled by a slide-valve 6 which is pierced with the apertures or ports 7 and moves in co-operation with a stationary wall 8 having therein the ports 9. An electro-magnet 10 controls the opening or' the said valve, the same being closed by the spring 11.

The exhaust slide valve consist-s of the pole-piece 12 of an elecrto-magnet 13, which serves to regulate the e'lort exercised by the latter; the said valve moves in 'front of the ports let provided in the wall ot the cylinder 3. and connects vthem with the ports 15 pierced in the external wall et the said main body o'l the apparatus. rThe slide valve 12 is urged by the reaction spring 16 which maintains it normally in the position in which the ports 141 are closed.

The ports 17 are formed in the wall oi the cylinder 3 somewhat above the position occupied by the striker 4; when at the bottom of the stroke. Below the cylinder 3 is screwed a stationary sleeve 18 pierced with orifices 19 communicating with the atmosphere. Within the said sleeve is freely slidable within certain limits aco-operating member or anvil 20 wnich is pierced with the longitudinal ducts 21 and is adapted to enter into contact with the said striker, Whose 1notion it imparts to the tool. Below the handle 2 is disposed a switching device shown diagramn'iatically at 22 and controlled by the lever The operation is as follows:

lhen the said striker is accurately disposed upon the piece ot work, the thrust eX- ercised thereon through the medium of the tool will cause the said anvil to assume the pper position, Fig. 1, and the air which has passed under the striker along the walls thereot which are, of course, not air-tight can escape through the orifices 21 and 19. This being the case, the switch 22 being placed in the position corresponding to the operation of the apparatus, whilst the striker is supposed to be at the upper end of the stroke, current is sent into the electro-inagnet 10; the latter will upwardly attract the valve (i and will bring the ports 7 in line with the ports 9. The compressed air now acts upon the said hammer which descends, thus ijiroducing an impact upon the said anvil which imparts it to the tool. During this movement, since the electro-magnet 13 is not energized, the valve 12 will now be acted upon by its return spring 16 and will close the exhaust orifices 14;. The striker 4 is subject to a rebound, and upon attaining the lower end ot the stroke, the air situated above the same will be discharged through the orifices 1.7.

Atthis moment the circuit of the electromagnet 10 having been previously broken the circuit of the electro-magnet 13 is closed. Under the action of the spring 11, the valve 6 resumes its initial position, thus closing the ports 9; the electro-magnet 13 attracts both the said striker, which now rises, and the valve 12 which uncovers the ports 141, thus providing for the discharge of the air which has remained above the said striker. The movement is then continued in the same cycle of operations.

Should the tool be no longer in contact with the piece ot work the said anvil will 'liall by its own weight to its lower position; the ports 21 will be closed, and the air situated below the said striker, which is unable to escape will form a cushion absorbing the shocks produced it the hammer is improperly set in operation.

The motor su) l inf" the said hammer with electric current and compressed air is shown diagrammatically in Fig. 2; this motor 24 which is an electric motor in the example represented drives the alternator 25 by direct coupling. 1t also controls through the electro-magnetic clutch 26 and the gearing 27, the air compressor 28; the air delivered by the latter is stored in the tanks 29, 29', and a pressure regulator 30 edects the clutching at 26 when the pressure in said tanks attains a certain value. The clutch 26 is as above stated supplied with current from a shunt circuit upon 'the exciter armature or' the alternator'. The alternating current required 'for the electro-magnets 10 and 13 of the hammer is supplied to the latter through the rotatable switch 31, Fig. l, which comprises an insulating disc 32 rotating on an axis 33 and provided on the one hand with a circular conducting ring 34 and on the other hand with vtwo conducting sectors 35 and 36 which are situated at unequal distances from the centre. he said ring co-operates with a brush 37 which is connected by a wire 38 to one pole ot the alternating current circuit ot the alternator. The sectors 35 and 3G are in permanent electrical connection with the said ring.

The brushes 39 and 10 coeoperate respectively with the sectors 35 and 3G, and are connected on the one hand by the wires 41 and 12 to the two poles of the continuous current circuit oi the alternator, and on the other hand resilriectively to the electroenagnets 10 and 13 by the wires li-.-B and 41. r the said electro-magnets are also connected to the switch 22, disposed upon the hammer, this being shown in Fig. l; said switch coinprises two contact pieces and which are on the one hand respectively connected to the wires 43 and 14 situated outwardly of the said electro-magnets; the switch also comprises the Contact piece 17 which .is connected by the wire 118 with the second pole of the alternating current circuit of the alternator. (lo-operating with the contact piece 47 are two contact pieces 49 and 50 which are respectively connected by the wires 5l and 52 with the electro-magnets l0 and 13. A suitable resistance 53 is disposed between the wires' 5l and 'll e said switch further comprises a movable contact piece 54 co-operating with the above-mentioned stationary7 contact pieces. rlhe winding' ot the electroirignctic clutch is ini-'ert-ed in wire 42; the pressure regulator 3() is adapted to open the circuit et wire 42 when the pressure in the compressor increa, above a certain limit and the compresse'u air moves the pifton (liigz) towards the right hand side ot the ligure against the action oi its spring 30. This movement ot the piston 30 draws apart the contact parts 42 inserted in the wire 42.

The diagr `m (ll Shows in full lines the voltage curve and in dotted lines the current curve which, as illustrated, is 90 out of phase with the voltage curve. in the example shown the ratio between the frequencies of the alternator and the striker is 3. 'lhe current is allowed to tlow between a n axin'ium and a minimum of the voltage in order to provide tor the intensity rising gradually to a maximum and then decreasingl gradually. Between A and B, the current flows in the electro-magnet l0 `which opens the inlet valve, and the air thus enters the cylinder; the circuit is broken after the point l, the striker continues upon its stroke and the air in the cvlind r will thus expand. From C to D, the circuit ot the electroanagnot 13 is closed, and the latter actuates the striker 4 and the discharge valve l2. rlie striker, after rebounding, will be brought to the rea-r under the attraction ot the electromagnet i3. When the voltage is about to attain zero adliacent the point D, and consequently its intensity at a maximum, the valve returns to the rear and closes the discharge ports. A certain pressure will prevail above the striker 4 and will arrest its motion then at the point E the admission of air will recommence.

Fig'. 4 is a general ciagrani oit the electricaily-operated valve gear.

llt the switch Q2 ot the striker is in the inoperative position, i. e. it the movable contact member 54 connects together the contact pieces and 46, no alternating current will be supplied, even vwhen the contact segn'ient comes under the brush 39 or the segment 36 under the brush 4 however the continuous current will proceed through the wires 4l and 43, the contact piece 45, the contact member 54, the contact piece 46, the wires 44 and 42, and the clutch 26. rlhe air compressor Q3 is thus connected to the motor 4 and supplies coniipressed air to the tanks 29, the hammer being in the inoperative position.

Buit it the movable Contact member 54 of the switch 22 connects together the contact pieces 47 and 49, while the contact segment 36 comes under the brush 40, the alternating current will proceed through the wire 33, the brush 37, the ring` 34, the contact segment 36, the brush 40,'the wire 44, the electi.'onia, ,gnet 13, the wire 52, the Contact piece 4S), the contact pieces 54 and 47, and the wire 43. The electro-magnet 13 will be thus energized and it thus brine-s back the striker 4 and attracts the valve l2. ln like manner, when the segment 35 comes under the brush the alternating` current passes through the wire 38, t-he brush 37, the ring 34, the segment 35, the brush 39, the wire 43, the electro-magnet l0, the wire 51, the resistance 53, the contact piece 49. the contact member 54, the contact piece 47 and the wire 43. Due to the resistance 53, the electro-magnet 10 will only partially open the inletl valve 6, so that the said striker will operate with diminished power. 1

During all these operations, the continuous current circuit remains broken and the compressor 23 is inoperative.

The movable contact member 54 may iurther connect together the contact pieces 49 and 50 and the contact piece 47. In this event, when the segment 35 comes under the brush 39, the current will proceed through the wire 33, the brush 37, the contact piece 35, the brush 39, the wire 43, the electro magnet 10, the wire 5l, the Contact piece 50, the contact member 54, the contact piece 47 and the wire 43. The resistance 53 will row b short-circuited, and the electro-magnet l0 allows the full admission of the compressed air into the cylinder As above stated, the clutch 26 connectingq the motor to the compressor has its circuit broken not only when the h ammeris in operation, when 54 is between the contact parts 45 and 46 but also under the action of the pressure regulator 3() when the pressure becomes sulicient in the tanks'QQ, 29.

T he wires 43, 44 and 43 a e brought to the hammers through the compressed air supplv tube 5 and are connected to the internal wiring` of the. said electro-magnets and the switch 22 by movable Contact plug and socketpieces, so that when the 'flexible tube isremoved .trom the hammer, the wires are disconnected at the same time. rlhe socket portions 55 oi the said plug' devices are atiached to the wires within the said tube in order to reduce the danger oit slioil-ciicuit ing to a minimum should the generator be improperly put in operation. The wires secured to the plugs 56 are connected to double insulated terminals traversing' plate in insulatingmateria 57 so as to allow their airtightpassage from the compressed air inlet chamber 5 to the terminals or" the switch 22 and back again to the chamber 5 and the Wires proceeding to the electro-magnets are also brought out by means of double insulated terminals.

Obviously, the various details of construction asV above set 'forth are given solely by Way of example and are susceptible of numerous modifications Without departing from the `principle ot' the invention.

lVhat I claim is:

l. Anelectropneumatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series of ports connecting the compressed air chamber with the cylinder, a closing device for these ports, an electromagnet controlling said closing device, a series of exhaust ports for the compressed air in the Wall of the cylinder, a second closing device 'for these exhaust ports, aseoond electromagnet controlling said second closing device and an alternator supplyingcurrent to both electromagnets.

2. An electropneumatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series of ports connecting the compressed air chamber with the cylinder, a closing device for these ports, an electromagnet controlling said closing device, a series ot exhaust ports for the compressed air in the Wall of the cylinder, a second closing device `for these exhaust ports, a second electromagnet controlling said second closing device and adapted to control the return movement of the striker and an alternator supplying current to both electromagnets.

2%. An electropneumatic hammer compris` ing a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series of ports connecting the compressed air chamber with the cylinder, a closing device ior these ports, an electromagnct controlling. the said closing device, a series of exhaust ports for the compressed air in the Wall et the cylinder, a second closing device for these exhaust ports, a ,second electromagnet controlling the said second closing device and adapted to control the return movement of the striker, a second series of exhaust ports above lowest position of the striker and an alternator supplying current to both electromagnets.

l. An electropneumatic hammer ,comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series of ports connecting the compressed air ch amber With the cylinder, a slide valve for these ports, reaction springs holding said valve closed, an electromagnet adapted to open said valve, a series of exhaust ports for the compressed air in the Wall of the cylinder, a second slide valve for these exhaust ports, a. spring device holding said second slide valve closed, a second electroniagnet controlling last mentioned valve and adapted to provide for the return movement of' the striker after the impact and an alternator supplying current to both electromagnets.

5. An electropneumatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series ot ports connecting the compressed air chamber With the cylinder, a slide valve for these ports, reaction springs holding said valve closed, an electromagnet adapted to open said valve, a series of exhaust ports for the compressed air in the Wall or' the cylinder', a second slide valve for these exhaust ports, a spring device holding said second slide valve closed, a second electromagnet controlling last mentioned valve, and adapted to provide for the return movement of the striker after the impact and an alternator supplying current to both electromagnets with alternating current the frequency of which is greater than that of the impacts.

6. An electropneumatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber, a series of ports connecting the compressed air chamber with the cylinder, a slide valve for these ports, reaction springs holding said valve closed, an electromagnet adapted to open said valve, a series et exhaust ports for the compressed air in the Wall olf the cylinder, a second slide valve for these exhaust ports, a spring device holding said second slide valve closed, a second electromagnet controlling last mentioned valve and adapted to provide for the return movement of the striker after the impact, an alternator supplying current to both electromagnets and a rotatable switch controlling the supply of alternating current.

7. An electropnemnatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said I chamber', a series of ports connecting the compressed air chamber with the cylinder, a slide valve for these ports, reaction springs holding Vsaid valve closed, an eleotromagnet adapted to open said valve, va series of exhaust ports for the compressed air in the Wall of the cylinder, a second slide valve `for these exhaust ports, a spring device holding said second slide valve closed, a second electromagnet controlling last mentioned valve and adapted to provide for the return movement of the striker after the impact, a movable` anvil under the striker, discharge orifices in the lower part of the cylinder connecting the lower surl'ace ol' the striker with the atmosphere and closed by the anvil when latter is at its lower position and an alternator supplying current to both electromagnets.

8. An electropneumatic hammer comprising cylinder, a striker sliding in said cylinder, a compressed air chamber above said cylinder, a series of ports connecting the compressed air chamber With the cylinder, a slide valve for these ports, reaction springs holding said valve closed, an electromagnet adapted to open said valve, a series of eX- haust ports t'or the compressed air in the wall ot the cylinder, a second slide valve for these exhaust ports, a second series of springs holding said second slide valve closed, a second electromagnet controlling last mentioned valve and adapted to provide for the return movement ot' the striker after the impact, a compressor, a flexible conduit connecting the compressor With the compressed air chamber, an alternator supplying current to both electromagnets, a motor actua-ting the alternator and the compressor, an electromagnetic clutch fed by the alternator for connecting the compressor with the motor and a switch connecting the alternator in one position with the electromagnets and in another With the electromagnetic clutch.

9. An electropneumatic hammer comprising a cylinder, a striker sliding in said cylinder, a compressed air chamber abo-ve said cylinder, a series of ports connecting the compressed air chamber With the cylinder, a slide valve for these port-s, reaction springs holding said valve closed, an electromagnet adapted to open said valve, a series of eX- haust ports t'or the compressed air in the Wall ot the cylinder, a second slide valve for these exhaust ports, a device holding said second slide valve closed, a second electromagnet controlling last mentioned Valve and adapted to provide for the return movement of the striker after the impact, a compressor, a flexible conduit connecting the compressor With the compressed air chamber, an alternator supplying current to both electromagnets, a motor actuating the alternator and the compressor, an electromagnetic clutch :ted by the alternator for connecting the compressor With the motor, and means for controlling the electric connection between the alternator and the electromagnetic clutch.

l0. An electropneumatic hammer comprising a cylinder, a striker' sliding in said cylinder, a compressed air chamber above said cylinder, means for feeding air into said chamber, a series of ports connecting the compressed air chamber With the cylinder, a slide valve for these ports, reaction springs holding said valve closed, an electromagnetadapted to open said valve, a series of eX- haust ports for the compressed air in the Wall ot' the cylinder, a second slide valve for these exhaust ports, a spring device holding said second slide valve closed, a second electromagnet controlling last mentioned valve and adapted to provide for the return movement of the striker after the impact, resistance coils adapted to be inserted in'the circuit of the electromagnet irst mentioned and an alternator supplying current to-'both electromagnets.

In Witness Whereol I have hereunto set my hand.

ALBERT CHARLES JAMES GUENE.

'Ill 

